Yeah I just tested this out before you added the note to the top of your message. I found that it did have an effect, no doubts about that, but it was very minor. I opened up around 100 materials/blueprints and meshes and managed to go from 600mb to 800mb.
I would need to open another 1000 or so for it to have the same effect, and that just doesn’t happen under regular use.
Thanks for the info 
EDIT: also wanted to add since it was asked above to erWilly, I use a two monitor setup and place the Content Browser on the second screen (and sometimes work on BP/Materials on the 2nd screen). Not sure that helps at all, but thought I would mention it.